Big array with data managed by another value

[Romain Beauxis <toots@rastageeks.org>]

	Hi all !

In our application, we use a custom block to carry a pointer to data allocated 
by C.

We would like to use this data with functions that use Bigarrays. Hence, we 
want a [custom_to_bigarray] function that would allocate a big array, and put 
our pointer as its data.

We can pass the CAML_BA_EXTERNAL flag to the bigarray, so that the Gc doesn't 
touch data pointer when deallocating the returned array. 

However, what I don't know how to do yet is to also tell the Gc that the 
original value should not be deallocated until we have finished dealing with 
the returned bigarray.

Is there a clean way to do that ?


Romain